if it was a shp it may have been buzz off, and if it was then they would have done as little as possible to get the job done. for the spark are you not getting spark at the plug tip? the spark plug boot? or the dizzy terminals? also is it all 4 not sparking or is at least one sparking? depending on where you get spark, if any, that will tell you where the breakdown is. I would check a wiring diagram to see which wires give a signal and power to your dizzy. then check those wires for power, if no power then check the other end of the wire ( ecu ) to see if power is there. it may be a broken wire or a bad ecu, or a bad dizzy. but since the only part of your engine that the alarm has anything to do with is the starter kill relay I would give 100:1 that it isn't the alarm.

the alarm hooks to +12v, ground, your horn (option), parking lights, siren (option), door trigger, dome light (option), valet switch, led, starter kill relay ( which itself hooks 2 terminals to the starter wire, 1 from the key and 1 to the starter, then 1 terminal to +12v, and 1 to the alarm for -ground input). and that is the alarm at its basic, and since you say its old I would say it may even be easier than that.

If you want the alarm in your car to have an alarm thats all good its one of the first steps I tell people to do when they get a ride without one, just don't expect it to fix the problem.